1. Field of the Invention
The field of the invention relates to filtration systems. In particular, the field of the invention relates to systems suitable for use in gas turbines for filtering inlet air to remove contaminants therefrom, across a variety of conditions.
2. Description of Related Art
Filter systems for gas turbine inlet air are known. Power generation equipment such as gas turbine engines use a large supply of intake air to enable combustion. To maintain suitable performance and reliability of the turbine the intake air is filtered to remove unwanted dust, moisture and other contaminants. Filters are generally subject to accumulation of particulates on and in the filter media over time, which adversely increases resistance to flow through the filters. Often, back-pulsing of air is used to clean the filters intermittently.
Various filter media are known for filtering inlet air and they are generally tailored to optimise filtration of specific contaminants and to take into account geographic or environmental conditions. Gas turbines are used across a wide variety of environments, for example from deserts to offshore platforms.
Filtration system design often requires a tradeoff between performance parameters, usually between pressure loss, filter life, and efficiency, although other parameters such as performance in moist or humid conditions also play a part. These parameters usually compete against each other, i.e. higher filtration efficiency usually requires a higher pressure loss across the media, reducing the producible energy as a function of the induced air. Known approaches to addressing complex filtration performance requirements include the use of multiple filtration stages and/or the use of multiple layers of filtration media. The pressure loss over each filtration stage is additive. Thus an improved filtration system and method of designing such is required.